Do you have any more of that gas or starting fluid?
If so, try some of that right in the intake or throttle body or if you have to the brake booster hose if you cannot find a spot. If it starts with starting fluid, the problem is in the fuel system. So then, listen if the fuel pump runs when you first turn the key to run. If not check the fuse and if ok, let me know and we will check the relay. If the pump does run, check the fuse for the fuel injector/s and if ok, make sure you have power to the fuel injectors with the key on run and start. if so, check the ground pulse with a noid light while cranking.
If it don't start with starting fluid, check for spark. If you have spark, remove a few spark plugs and smell them for being gas fouled.
You can make a test plug with a new spark plug and some wire, a mini hose clamp and an alligator clip. First open the spark plug gap to around 0.075” and strip both ends of a 16 gauge wire about 4 foot in length. Attach the mini hose clamp around the threads of the spark plug cause that is a ground and secure it with the mini hose clamp with the bare wire end in between to make a good connection. Next, take the other end of wire and secure to an alligator clip. Now, you have a test plug. Remove any spark plug boot you want and insert your test plug onto the spark plug wire end you just pulled off and ground the alligator clip. Lay the spark plug in some shade somewhere under that hood and then crank the engine and look for spark. It should crackle with sound and should be blue but red is ok, orange is a little weak. If it can jump that 0.075” gap you should have no problem igniting an engine. You can also use that to check coils on some vehicles.
If I put the gas where you indicated (though I am not quite sure where that is) and the car does in fact start, do you believe it is a safe bet for me to try to get 50 miles on a highway?
No, that is only to test if it's the fuel system or not. The engine will die as soon as it burns up the gas or starting fluid but at least you or I will know if the problem is with the fuel system.
Does the fuel pump run when you first turn the key to run?
yes, it sounds like it has started, but only for a split second.
Yes, than that means the problem is with the fuel system.